From 7b59e10a8305acc4c31f31fa9ca063b94d860159 Mon Sep 17 00:00:00 2001
From: Hiroshi Ogawa <hi.ogawa.zz@gmail.com>
Date: Tue, 23 Apr 2024 16:13:32 +0900
Subject: [PATCH] feat: replace `any` with `unknown` for default types

---
 packages/spy/src/index.ts  | 10 +++++-----
 test/core/test/spy.test.ts |  2 +-
 test/core/test/vi.spec.ts  | 13 +++++++++++--
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/packages/spy/src/index.ts b/packages/spy/src/index.ts
index db22a60ccd3a..a9dfcc70fe04 100644
--- a/packages/spy/src/index.ts
+++ b/packages/spy/src/index.ts
@@ -92,8 +92,8 @@ export interface MockContext<T extends Procedure> {
   lastCall: Parameters<T> | undefined
 }
 
-// TODO: use `(...args: unknown[]) => unknown` for stricter default like jest?
 type Procedure = (...args: any[]) => any
+type UnknownProcedure = (...args: unknown[]) => unknown
 
 type Methods<T> = keyof {
   [K in keyof T as T[K] extends Procedure ? K : never]: T[K];
@@ -117,7 +117,7 @@ Jest uses the latter for `MockInstance.mockImplementation` etc... and it allows
   const boolFn: Jest.Mock<() => boolean> = jest.fn<() => true>(() => true)
 */
 /* eslint-disable ts/method-signature-style */
-export interface MockInstance<T extends Procedure = Procedure> {
+export interface MockInstance<T extends Procedure = UnknownProcedure> {
   /**
    * Use it to return the name given to mock with method `.mockName(name)`.
    */
@@ -249,14 +249,14 @@ export interface MockInstance<T extends Procedure = Procedure> {
 }
 /* eslint-enable ts/method-signature-style */
 
-export interface Mock<T extends Procedure = Procedure> extends MockInstance<T> {
+export interface Mock<T extends Procedure = UnknownProcedure> extends MockInstance<T> {
   new (...args: Parameters<T>): ReturnType<T>
   (...args: Parameters<T>): ReturnType<T>
 }
 
 type PartialMaybePromise<T> = T extends Promise<Awaited<T>> ? Promise<Partial<Awaited<T>>> : Partial<T>
 
-export interface PartialMock<T extends Procedure = Procedure> extends MockInstance<(...args: Parameters<T>) => PartialMaybePromise<ReturnType<T>>> {
+export interface PartialMock<T extends Procedure = UnknownProcedure> extends MockInstance<(...args: Parameters<T>) => PartialMaybePromise<ReturnType<T>>> {
   new (...args: Parameters<T>): ReturnType<T>
   (...args: Parameters<T>): ReturnType<T>
 }
@@ -514,7 +514,7 @@ function enhanceSpy<T extends Procedure>(
   return stub as any
 }
 
-export function fn<T extends Procedure = Procedure>(
+export function fn<T extends Procedure = UnknownProcedure>(
   implementation?: T,
 ): Mock<T> {
   const enhancedSpy = enhanceSpy(tinyspy.internalSpyOn({ spy: implementation || (() => {}) }, 'spy'))
diff --git a/test/core/test/spy.test.ts b/test/core/test/spy.test.ts
index 35cddb90374a..719160540b01 100644
--- a/test/core/test/spy.test.ts
+++ b/test/core/test/spy.test.ts
@@ -15,7 +15,7 @@ describe('spyOn', () => {
 
   test('infers a class correctly', () => {
     vi.spyOn(mock, 'HelloWorld').mockImplementationOnce(() => {
-      const Mock = vi.fn()
+      const Mock = vi.fn<any>()
       Mock.prototype.hello = vi.fn(() => 'hello world')
       return new Mock()
     })
diff --git a/test/core/test/vi.spec.ts b/test/core/test/vi.spec.ts
index 86cacc412462..5de26f05f495 100644
--- a/test/core/test/vi.spec.ts
+++ b/test/core/test/vi.spec.ts
@@ -41,6 +41,15 @@ describe('testing vi utils', () => {
     })
     expectType<MockedFunction<() => boolean>>(vi.fn(() => true))
     expectType<MockedFunction<() => boolean>>(vi.fn())
+
+    expectType<MockedFunction<() => boolean>>(vi.fn<() => boolean>(() => true))
+    expectType<Mock<() => boolean>>(vi.fn<() => boolean>(() => true))
+    expectType<() => boolean>(vi.fn(() => true))
+
+    // @ts-expect-error default unkonwn
+    expectType<(v: number) => boolean>(vi.fn())
+
+    expectType<(v: number) => boolean>(vi.fn<any>())
   })
 
   test('vi partial mocked', () => {
@@ -57,7 +66,7 @@ describe('testing vi utils', () => {
     })
 
     vi.mocked(mockFactory, { partial: true, deep: false }).mockReturnValue({
-      bar: vi.fn(),
+      bar: vi.fn<FooBar['bar']>(),
     })
 
     vi.mocked(mockFactory, { partial: true, deep: true }).mockReturnValue({
@@ -71,7 +80,7 @@ describe('testing vi utils', () => {
     })
 
     vi.mocked(mockFactoryAsync, { partial: true, deep: false }).mockResolvedValue({
-      bar: vi.fn(),
+      bar: vi.fn<FooBar['bar']>(),
     })
 
     vi.mocked(mockFactoryAsync, { partial: true, deep: true }).mockResolvedValue({